ecosystem ecology

Twice humans have witnessed the wasting of snow and ice from Peru’s tallest volcano, Nevado Coropuna—In the waning of the last ice age, some 12,000 years ago, and today, as industrial carbon dioxide in the air raises temperatures again. As in the past, Coropuna’s retreating glaciers figure prominently in the lives of people below.

Eight hundred years ago, relatively small armies of mounted warriors suddenly exploded outward from the cold, arid high-elevation grasslands of Mongolia, and conquered the largest contiguous empire in history. Led by Genghis Khan and his sons and grandsons, the Mongols briefly ruled most of modern-day Russia, China, Korea, southeast Asia, Persia, India, the Middle East and eastern Europe. They reshaped world geography, culture and history in ways that still resound today. How did they do it? Among the forces at work: the Mongols’ fast horses and brilliant cavalry tactics; their openness to new technologies; and the political genius of Genghis himself. Now, a research group is looking into a possible other factor: climate change. The idea may have implications not only for our understanding of history, but for modern Mongolia and the wider world.